Download or read book Structure And Dynamics Of Charged Colloidal Disks In Colloid Polymer Mixtures written by Suhasini Kishore and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Complex fluid mixtures of colloids and polymers are extensively used in several conventional and emerging technological applications. Particles self-assemble under different conditions to form colloidal glasses and gels and it often leads to the development of unusual viscoelastic features. In the case of aspherical particles, shape anisotropy and physical aging effects add to the existing complexities so the implementation of a strategic formulation method to improve performance and stability remains a critical challenge. This thesis presents a comprehensive analysis of particle interactions in mixtures of charged disk-shaped colloids and weakly-adsorbing polymers like poly(ethylene oxide) (PEO). Here, we discuss the behavior of suspensions containing laponite® and PEO of molecular weights (Mw) varying between 4.6 and 300 kg/mol and at concentrations within the dilute through concentrated regimes. Techniques such as rheology, light (DLS) and x-ray scattering (XPCS and USAXS) were used to understand and characterize the effect of chain number and length on the macroscopic behavior, microstructure and dynamics of particles in these colloid-polymer mixtures. Laponite® suspensions gradually transition from a homogeneous fluid to a structurally arrested phase. With the addition of polymers, rheological measurements show that in addition to the typical re-entrant behavior observed in the dilute polymer phase, there is another onset of stabilization close to the semi dilute polymer regime. While DLS and XPCS results show three different regimes in the microstructural dynamics along these transitions, USAXS measurements indicate the presence of only finite sized ellipsoidal structures that are directed by polymer-particle interactions. We believe that the arrested phase is a glassy system as no large scale structure is observed. On the other hand, adding high Mw PEO results in the formation of strong colloidal gels where laponite® particles act as junctions in the colloid-polymer network. Nanometer to micron-sized clusters form with the addition of PEO chains larger than the minimum required for polymer-clay bridging. Increasing the concentration of PEO changes the density of clusters and this directly affects the bulk elasticity of the material. The results thus serve as an excellent benchmark to understand how to effectively formulate an anisotropic colloid-polymer mixture for an application.
Download or read book Structure and Dynamics of Charged Colloid polymer Mixtures written by Miguel Alberto Peláez Fernández and published by . This book was released on 2012 with total page 209 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Dynamics of Colloid polymer Solutions written by Ji Yeon Huh and published by ProQuest. This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Dynamics of Strongly Interacting Colloids and Supramolecular Aggregates in Solution written by Sow-Hsin Chen and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 848 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last decade, various powerful experimental tools have been developed, such as small angle X-ray and neutron scattering, X-ray and neutron reflection from interfaces, neutron spin-echo spectroscopy and quasi-elastic multiple light scattering and large scale computer simulations. Due to the rapid progress brought about by these techniques, one witnesses a resurgence of interest in the physicochemical properties of colloids, surfactants and macromolecules in solution. Although these disciplines have a long history, they are at present rapidly transforming into a new, interdisciplinary research area generally known as complex liquids or soft condensed matter physics: names that reflect the considerable involvement of the chemical and condensed matter physicists. This book is based on lectures given at a NATO ASI held in the summer of 1991 and discusses these new developments, both in theory and experiment. It constitutes the most up-to-date and comprehensive summary of the entire field.
Download or read book Structure Dynamics and Properties of Dispersed Colloidal Systems written by and published by Steinkopff. This book was released on 2013-11-20 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 38th General Meeting of the German Colloid Society was held at the University of Essen, Germany, from September 29th to October 2nd, 1997. The selection of papers presented in this volume covers a broad range of fundamental aspects as well as recent developments. - It focuses the following sections: - Technical applications; - Advanced experimental techniques; - Thin films and interfaces; - Suspensions and microcapsules; - Emulsions, microemulsions and foams; - Macromolecules; - Association colloids; - Colloidal systems in environmental science.
Download or read book Colloids and the Depletion Interaction written by Henk N.W. Lekkerkerker and published by Springer Science & Business Media. This book was released on 2011-05-12 with total page 245 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloids are submicron particles that are ubiquitous in nature (milk, clay, blood) and industrial products (paints, drilling fluids, food). In recent decades it has become clear that adding depletants such as polymers or small colloids to colloidal dispersions allows one to tune the interactions between the colloids and in this way control the stability, structure and rheological properties of colloidal dispersions. This book offers a concise introduction to the fundamentals of depletion effects and their influence on the phase behavior of colloidal dispersions. Throughout the book, conceptual explanations are accompanied by experimental and computer simulation results. From the review by Kurt Binder: "They have succeeded in writing a monograph that is a very well balanced compromise between a very pedagogic introduction, suitable for students and other newcomers, and reviews of the advanced research trends in the field. Thus each chapter contains many and up to date references, but in the initial sections of the chapters, there are suggested exercises which will help the interested reader to recapitulate the main points of the treatment and to deepen his understanding of the subject. Only elementary knowledge of statistical thermodynamics is needed as a background for understanding the derivations presented in this book; thus this text is suitable also for advanced teaching purposes, useful of courses which deal with the physics for soft condensed matter. There does not yet exist any other book with a similar scope..... The readability of this book is furthermore enhanced by a list of symbols, and index of keywords, and last not least by a large number of figures, including many pedagogic sketches which were specifically prepared for this book. Thus, this book promises to be very useful for students and related applied sciences alike." Eur. Phys. J. E (2015) 38: 73
Download or read book Colloidal Self Assembly written by Junpei Yamanaka and published by Springer Nature. This book was released on 2023-11-04 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: This concise book covers fundamental principles of colloidal self-assembly and overviews of basic and applied research in this field, with abundant illustrations and photographs. Experimental and computer simulation methods to study the colloidal self-assembly are demonstrated. Complementary videos "Visual Guide to Study Colloidal Self-Assembly" on the research procedures and assembly processes are available via SpringerLink to support learning. The book explains basic elements of mechanics and electromagnetism required to study the colloidal self-assembly, so that graduate students of chemistry and engineering courses can learn the contents on their own. It reviews important research topics, including the authors' works on the colloidal self-assembly of more than 30 years’ work. The principal topics include: (1) crystallization of colloidal dispersions, with the emphasis on the role of surface charges, (2) fabrication of large and high-quality colloidal crystals by applying controlled growth methods, (3) association and crystallization by depletion attraction in the presence of polymers, (4) clustering of colloidal particles, especially those in oppositely charged systems, and (5) two-dimensional colloidal crystals. Furthermore, it covers (6) applications of colloidal crystals, ranging from cosmetics to sensing materials. We also describe space experiments on colloidal self-assembly in the International Space Station. This book will interest graduate school students in colloid and polymer science, pharmaceutics, soft matter physics, material sciences, and chemical engineering courses. It will also be a useful guide for individuals in academia and industry undertaking research in this field.
Download or read book Charged Colloids and Proteins written by Marco Heinen and published by Forschungszentrum Jülich. This book was released on 2011 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Colloidal Interactions on Formation of Glasses Gels Stable Clusters and Structured Films written by Anand Kumar Atmuri and published by . This book was released on 2013 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal suspensions are ubiquitous because of their vast industrial and household usage. We demonstrate that interactions between colloidal particles play a crucial role in manipulating the phase behavior and thereby the macroscopic properties of a variety of colloidal materials, including structured films, gels, glasses and stable clusters. First, we examined films comprised of two different colloidal particles and investigated the impact of colloidal interactions in manipulating the extent of segregation in the dried films. A transport model was used to predict the volume fraction profiles of the particles as a function of film thickness, which showed that segregation could be altered by changing the particle interactions. Experimental studies were carried out using different charged latex particles and varying the pH to change the interactions, and the results from experiments and model show a very good agreement to capture the extent of segregation. Second, we studied the effect of adding low molecular weight adsorbing and non-adsorbing polymers to suspensions to modify the interparticle interactions. We studied the structural dynamics and bulk rheology of a disk-shaped clay colloid, laponite®, and polymer. Under basic conditions laponite® forms a repulsive colloidal glass. We show that low concentrations of an adsorbing polymer retards glass formation, whereas at higher concentrations an attractive glass is formed. Thus, we obtain a type of re-entrant glass transition, which is a first of its kind observed in anisotropic colloids with adsorbing polymer. On the other hand addition of a non-adsorbing polymer to laponite® suspensions triggers the formation of particle clusters, and increasing the concentration of polymer increases the strength of attraction between the particles and the size of the clusters. To further understand formation of stable clusters, we utilized population balance equations (PBE) models to study aggregation of charged colloids under quiescent conditions. We considered particles with a DLVO-type potential, where the interactions are a sum of van der Waals attraction and electrostatic repulsion. Under certain conditions, the net repulsion between large aggregates and a single particle acts as a barrier against further aggregation, and clusters reach a stable size. The PBE model was used to map out regimes of uncontrolled aggregation, controlled aggregation, and no aggregation as a function of ionic strength and colloid weight fraction. The model was tested using experimental data on charged latex particles with different colloid weight fractions and ionic strengths. The model was able to predict the regime of controlled aggregation and final size of aggregates very well. However, the rate of aggregation predicted by the model was much faster than observed experimentally. Finally, we explored aggregation of latex particles in a shear environment similar to that used in industrial toner production processes. We studied the effect of temperature, pH and coagulant concentration on aggregation and showed that there is a optimum variable space to have aggregates of controlled size and distribution.
Download or read book Polymer Colloids written by Rodney Priestley and published by Royal Society of Chemistry. This book was released on 2019-12-02 with total page 442 pages. Available in PDF, EPUB and Kindle. Book excerpt: Academic and industrial research around polymer-based colloids is huge, driven both by the development of mature technologies, e.g. latexes for coatings, as well as the advancement of new materials and applications, such as building blocks for 2D/3D structures and medicine. Edited by two world-renowned leaders in polymer science and engineering, this is a fundamental text for the field. Based on a specialised course by the editors, this book provides the reader with an invaluable single source of reference. The first section describes formation, explaining basic properties of emulsions and dispersion polymerization, microfluidic approaches to produce polymer-based colloids and formation via directed self-assembly. The next section details characterisation methodologies from microscopy and small angle scattering, to surface science and simulations. The final chapters close with applications, including Pickering emulsions and molecular engineering for materials development. A comprehensive guide to polymer colloids, with contributions by leaders in their respective areas, this book is a must-have for researchers and practitioners working across polymers, soft matter and chemical and molecular engineering.
Download or read book Brownian Interactions in Colloid polymer Mixtures written by Mehdi Karzar Jeddi and published by . This book was released on 2014 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer mediated Phase Stability of Colloids written by Álvaro González García and published by . This book was released on 2019 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloid-polymer mixtures are subject of intensive research due to their wide range of applicability, for instance in coatings and food-stuffs. This thesis constitutes a fundamental investigation towards a better control over the stability of such suspensions. Through the chapters, different key parameters governing the stability of colloid-polymer mixtures are explored. How the colloid (pigment) shape and the effective polymer-colloid affinity modulate the stability of the suspension are examples of these key parameters. Despise the mostly theoretical results presented, the thesis is written in a format accessible to a broad scientific audience. Some of the equations of state presented might of direct use to experimentalists. Furthermore, new theoretical insights about colloid-polymer mixtures are put forward. These include four-phase coexistences in effective two-component, quantification of depletant partitioning at high colloidal concentrations, multiple re-entrant phase behaviour of the colloidal fluid-solid coexistence, and a condition where polymers are neither depleted nor adsorbed from/to the colloidal surface.
Download or read book An Introduction to Dynamics of Colloids written by Jan K. G. Dhont and published by Elsevier Science Limited. This book was released on 1996 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the few textbooks in the field, this volume deals with several aspects of the dynamics of colloids. A self-contained treatise, it fills the gap between research literature and existing books for graduate students and researchers. For readers with a background in chemistry, the first chapter contains a section on frequently used mathematical techniques, as well as statistical mechanics. Some of the topics covered include: • diffusion of free particles on the basis of the Langevin equation •the separation of time, length and angular scales; • the fundamental Fokker-Planck and Smoluchowski equations derived for interacting particles • friction of spheres and rods, and hydrodynamic interaction of spheres (including three body interactions) • diffusion, sedimentation, critical phenomena and phase separation kinetics • experimental light scattering results. For universities and research departments in industry this textbook makes vital reading.
Download or read book Structure and Dynamics of Highly Charged Colloidal Suspensions written by Fabian Westermeier and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1993 with total page 1206 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure and Dynamics of Confined Polymers written by John J. Kasianowicz and published by Springer Science & Business Media. This book was released on 2002-07-31 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers are essential to biology because they can have enough stable degrees of freedom to store the molecular code of heredity and to express the sequences needed to manufacture new molecules. Through these they perform or control virtually every function in life. Although some biopolymers are created and spend their entire career in the relatively large free space inside cells or organelles, many biopolymers must migrate through a narrow passageway to get to their targeted destination. This suggests the questions: How does confining a polymer affect its behavior and function? What does that tell us about the interactions between the monomers that comprise the polymer and the molecules that confine it? Can we design and build devices that mimic the functions of these nanoscale systems? The NATO Advanced Research Workshop brought together for four days in Bikal, Hungary over forty experts in experimental and theoretical biophysics, molecular biology, biophysical chemistry, and biochemistry interested in these questions. Their papers collected in this book provide insight on biological processes involving confinement and form a basis for new biotechnological applications using polymers. In his paper Edmund DiMarzio asks: What is so special about polymers? Why are polymers so prevalent in living things? The chemist says the reason is that a protein made of N amino acids can have any of 20 different kinds at each position along the chain, resulting in 20 N different polymers, and that the complexity of life lies in this variety.
Download or read book Simulating the Physical World written by Herman J. C. Berendsen and published by Cambridge University Press. This book was released on 2007-07-12 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The simulation of physical systems requires a simplified, hierarchical approach which models each level from the atomistic to the macroscopic scale. From quantum mechanics to fluid dynamics, this book systematically treats the broad scope of computer modeling and simulations, describing the fundamental theory behind each level of approximation. Berendsen evaluates each stage in relation to its applications giving the reader insight into the possibilities and limitations of the models. Practical guidance for applications and sample programs in Python are provided. With a strong emphasis on molecular models in chemistry and biochemistry, this 2007 book will be suitable for advanced undergraduate and graduate courses on molecular modeling and simulation within physics, biophysics, physical chemistry and materials science. It will also be a useful reference to all those working in the field. Additional resources for this title including solutions for instructors and programs are available online at www.cambridge.org/9780521835275.
